Hydrologic and carbon services in the Western Ghats: Response of forests and agro-ecosystems to extreme rainfall events

Overall summary

Properties and functions of natural forest ecosystems regulate how rainfall is partitioned into surface flow, sub-surface flow, ground-water and evapotranspiration and also the export of sediment in streams. They also determine how and how much carbon is fixed, stored and lost from these ecosystems. In general, the more carbon that a forest stores in its biomass, the less water that the forest releases into the stream. However, this is not necessarily true under tropical mixed landscapes subject to long-term and intense human use and also as degraded sites are reforested over decades. Information on how these two different types of functions are linked is sparse for tropical forest ecosystems, especially when these ecosystems are degraded by human-use. We know even less about how hydrologic and carbon functions of ecosystems respond to extreme rain events (lots of rain per hour) and high intensity rain. This is occurring with greater frequency and is likely to increase under future climate change in the Western Ghats and adjacent Deccan Plateau which supports livelihoods and needs of 160 Million people. Furthermore, the effects of such extreme rain events on agro-ecosystems in tropical landscapes are also largely unstudied, especially in relation to crop damage and soil loss.

One of the gaps in our knowledge is how such extreme rain storms are distributed over space and time, and how this spatial distribution of rain events interacts with different land-use and land-cover in large landscapes to influence hydrology and carbon dynamics. India is one of the global leaders in forestation including experimenting with natural species and large areas of degraded land has been restored or reforested over the past several decades for various benefits. Currently India is planning to reforest over 10 Million Hectares as part of a national plan (Green India Mission) to sequester carbon and help regulate global atmospheric CO2. These initiatives can transform the water and carbon budgets over large areas and also influence availability of water for agricultural use downstream.

The proposed project will use existing data and generate new data over three years to help answer some of these questions and fill gaps in our knowledge. This will help policy and decision makers understand the nature of extreme rainfall events and hydrologic and carbon regulatory effects of forest degradation and reforestation. It will also enable assessment of the ability of different ecosystems (natural forests, degraded forests, reforested sites and agro-ecosystems) to perform these functions under future conditions of high intensity or extreme rain events. It will also help agricultural planners determine the sustainability of agricultural land-use under conditions of extreme rain. The implementation of the Green India Mission will benefit from information on the best possible sites to target for restoration and with what type of vegetation.

This project will also generate major benefits to the global need for the most optimal strategies in tropical reforestation in which India is taking the lead. It will help guide the selection of watersheds for restoration under the countries watershed development programmes and contribute to policies that help conserve natural habitats and ensure the conservation of ecosystem goods and services.

Impact Summary
Who will benefit from this research?
Over £ 8 billion has been committed by the Govt. of India to various afforestation and watershed restoration programmes in the coming decade. This will result in significant changes to the land use in the Western Ghats and adjacent Deccan Plateau which supports over 150 million people through a gamut of ecosystem services.
Four groups of non-academic beneficiaries are expected. These include policy makers at the central and state govt. and committees formed for planning conservation and development of the Western Ghats region.
Agencies promoting large scale reforestation and afforestation as part of the Indian response to climate change. The Green India Mission under the National Action Plan on Climate Change is the major beneficiary of the project outcomes. The project will contribute the understanding of likely impact of the proposed planting of 10 million hectares by this initiative over 10 years.
Agencies promoting large scale watershed restoration programmes such as the Dept. of Land Resources (DLR) under the Ministry of Rural Development. Allocation made for this programme during the present five year planning period is nearly as much as the entire expenditure on watershed programmes since their inception in India. However the DLR has been unable to sanction any new projects in this plan period.
Conservation groups such as the Western Ghats Ecology Expert Panel who are trying to build a coherent framework for identification of ecologically sensitive areas in this bio-diversity hot-spot.
Riparian stakeholders, specifically waters users associations and farmer groups in rain-fed semi-arid regions under the project. These groups are often excluded from the decision making process and consultations which lead to policy changes that affect their lives.

How will they benefit from this research?
Specific consultations during seminars, workshops and stakeholder meetings are envisaged throughout the project period. A gamut of dissemination materials including policy briefs, video presentations, pamphlets are planned to be distributed to the stakeholders. In addition, detailed proceedings of seminars will be used to formalise the events.
Outcomes will inform policy by answering specific questions on the impact of large scale land cover and land use change, especially afforestation, on hydrological and carbon storage services of different ecosystems of the Western Ghats. It will also help establish what kinds of areas should be restored under conditions of extreme rainfall events under climate change.
The project will build protocols for prioritisation watersheds to help achieve the biggest "bang for the buck" in terms of hydraulic services. This will go a long way to improve the efficiency of these programmes which presently utilise arbitrary criteria for planning restoration in watersheds.
Conservation groups, including researchers and managers, stand to gain from a better understanding of vulnerability of ecosystems and ecologically sensitive areas to extreme climate events. This will help take more informed management decisions and review the protected area network in the region.
Changes in policy will have a direct impact on downstream stakeholders. These groups will be informed about results of the research and its relevance through mass media, web-sites and outreach materials.
The scientific approaches developed during the project will be useful to other tropical countries facing similar challenges with land use change and water cycle.

The project is expected to involve policy makers through seminars that feed into the policy frameworks. This is expected to take place about 2 1/2 years into the project.
Staff working on the project will gain from the transfer of expertise in field methods and analytical tools between the teams. Last, but not least, the publication of a book as a result of the workshop envisaged during period.